Objective changers for a microscope are available in different embodiments. For example, from the document DE 100 31 720 A1, an objective changer is described in which individual objectives can be transferred from an objective stock along a guide rail into their desired position. For this, stops for a safe positioning of the objective are provided in the desired position. Alternatively, an objective change can be performed along a mechanical curve element.
Further, it is described to provide objective changers with a turret mechanism in which individual objectives are arranged substantially along a circular line and can be rotated into their operating position along this circular line. Further, objective changers are described which implement an objective change via a combination of sequentially performed movements, namely via a lifting, a shifting and a subsequent lowering of an objective into its operating position. In doing so, the user has to turn and pull or, respectively, press a lever.
In particular for applications in the field of electrophysiology it is necessary that a sample table having a sample placed thereon is no longer moved after its positioning. On the one hand, this is because of the often existing basic touch sensitivity of the samples to be examined and, on the other hand, because of the fact that biological samples mostly require free access to the sample to allow well-directed manipulations on the sample during its examination.
Altogether it can be said that the objective changers described in the related art are, on the one hand, very expensively and elaborately structured and, on the other hand, do not allow “fixed stage” applications with a fixed sample table. In the case of objective changers, the sample table often has to be moved for changing an objective.